Add auto-delete branch on worktree remove

[everpcpc]

Summary

Add a setting to auto-delete the branch when removing a worktree and wire the IPC/UI flow to delete the branch using the worktree branch name.

Tests

• Unit Test
• Logic Test
• Benchmark Test
• No Test - Not run (UI + IPC change).

Type of change

• Bug Fix (non-breaking change which fixes an issue)
• New Feature (non-breaking change which adds functionality)
• Breaking Change (fix or feature that could cause existing functionality not to work as expected)
• Documentation Update
• Refactoring
• Performance Improvement
• Other (please describe):